Continuous-reading range and azimuth finder and predictor.



No. 735,547 PATENTED AUG. 4, 1903.

J. P. MEIGS & E. GATHMANN.

CONTINUOUS READING RANGE AND AZIMUTH FINDER AND PREDIOTOR.

APPLICATION FILED APR. 16, 1903.

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No. 735,547. 'PATENTED AUG. 4,1903.

J. P. MEIGS & E. GATHMANN. CONTINUOUS READING RANGE AND AZIMUTH FINDER AND PRBDIGTOR.

APPLICATION FILED APR. 16, 1903. N0 MODEL. 5 SHHBTS-SHEET 2- fittoznego n4: Nonms PETERS com No. 735,547. PATENTED AUG. 4, 1903. J. F. MEIGS & B. GATHMANN.

CONTINUOUS READING RANGE AND AZIMUTH FINDE R AND PRBDICTOR.

APPLICATION FILED APE.16, 190s. H0 MODEL. 5 SHEETS-SHEET a.

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APPLICATION FILED APR. 16, 1903.

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No. 735,547. PATENTBD AUG. 4, 1903.

J. PfMEIGS & E. GATHMANN. CONTINUOUS READING RANGE AND AZIMUTH FINDER AND PREDIOTOR.

APPLIGATION EILED APR. 16, 1903. N0 MODEL.

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UNrrED STATES Patented August 4, 190a.

PATENT OFFICE.

JOHN F. MEIGS AND EMIL GATHMANN, OF SOUTH BETHLEHEM, PENNSYL VANIA, ASSIGNORS TO BETHLEHEM STEEL COMPANY, OF SOUTH BETH- LElI-IElVl, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

CONTINUOUS-READING RANGE AND AZIMUTH FINDER AND PREDICTOR.

SPECIFICATION forming part of Letters Patent No. 735,547, dated August 4, 1903.

Application filed April 16. 1903. Serial No. 152,915. (No model.)

To all whom it may concern:

Be it known that we, JOHN F. MEIGs and EMIL GATHMANN, citizens of the United States, residing at South Bethlehem, in the county of Northampton and State of Pennsylvania,have invented certain new and useful Improvements in a Continuous-Reading Range and Azimuth Finder and Predictor, of which the following is a specification.

Our invention relates to azimuth and range finding in connection with movable targets; and it consists of means, including two instruments provided with sighting devices and pivoted intersecting arms and with certain scales and appliances upon one instrument, whereby not only to ascertain the range of the target, but also to indicate and estimate for the difference in range resulting from the change of position of the target between the time of firing and contact of the projectile, as well as for the time of flight of the projectile in reaching the target, in connection with a single gun or a battery, as fully set forth hereinafter and as illustrated in the accompanying drawings, in which Figure 1 is a plan indicating the general construction and arrangement of the station and distant instruments in respect to a battery of four guns and the target. Figs. 2 and 3 together constitute a side view of the station instrument and a part of its supportingpedestal. Fig. 4 is a plan of the rear portion of the station instrument with the telescope removed. Fig. 5 is a plan of part of the forward portion of the station instrument.

In carrying out our invention we make use of two instruments, which for the sake of distinction We designate as the station instrument A and the distant instrument B, and the straight line between these instruments constitutes the base-line of a triangle the other two sides of which meet at a distant moving object or target 0, as a war Vessel, the object of the arrangement being to properly direct the firing of one or more guns. As shown, there is a battery of four guns arranged, preferably, between the instruments.

Each instrument B is, in fact, a protractor and is provided with a graduated segmental plate 10, and concentric with the same is pivedges as m of the'two segmental plates or the V fixed points or graduations thereof are upon the base-line or both are parallel therewith.

The station instrument has pivoted at a point 22 concentric with the graduated plate an arm 29, carrying at the inner end a minutedial 82, and at a diiferent point 23 on the baseline is pivoted a frame 24, carrying a telescope or other sighting device 20, and the frame 24 is prolonged to form an arm 28, parallel with the axis of the telescope and intersected by the arm 29, the pivotal points 22 23 being separated a distance on the base, which bears a definite ratio to the length of the base-line. The arms 28 29 have longitudinal slots in which slide blocks 32 35, a pin 31 extending from the block 32 into the block 35 and having its axis in line with the point of intersection of the axes of the two arms.

When the telescope of the distant instrument is sighted upon the target and the arm 29 of the station instrument is brought parallel to the arm 13 of the distant instrumentthat is, when each arm indicates the same degree on the graduated plateand when the telescopes are both sighted upon the same pointof the target, the angle formed between the points 22 23 and intersecting point of the two arms 28 29 of the station instrument will be the same angle as that of the base-line, its terminal point, and the target itself and the actual dimensions of the smaller triangle will bear a definite proportion to those of the larger triangle.

From the above it follows that if both telescopes are moved to maintain in sight a point on the target and the arm 29 follows the movement of the arm 13, so as to be continually parallel thereto as the target changes position, on any change in the position of the target altering the dimensions of the larger triangle the smaller triangle will be correspondingly changed and therelative proportions preserved, and a reading of the range indicated by the smaller triangle will give the actual range of the target.

In order that the actual change of dimensions of the minor triangle may be visually indicated, we make use of a properly-proportioned scale F, which in its preferred form is a graduated tape 40, secured at one end 42, near the pivotal point 28, extending below the arm 28 and around a pulley 41, carried by a block 32, and carried backward along the frame 24 over a grooved pulley 44: on the frame and around a spring-actuated drum 45, which maintains the tape taut, while permitting it to be drawn forward and unwound from the drum as the block 32 is carried outward. After placing the telescope and the arm 18 of the distant instrument at the proper angle--that is, with the axis of the telescope 15 in line with any predetermined point of the moving targetthc operator at the distant instrument communicates the angle in degrees and minutes to an operator at the station instrument, who sets the arm 29 of thatinstrutnent at the same angle, bringing the said arm 29 consequently parallel to the line of sight of the distant instrument, and another operator at the station instrument at the same time adjusts the telescope so as to bring the telescope and the arm 28 in azimuth in line with the same point of the target, and the scale showing the distance between the points 23 31 of the station instrument will give the range of the target. The range thus given, however, will not indicate the position that the target moving to or from the gun or in any direction in relation thereto will occupy by the time a projectile can reach the same, and we therefore make use of what we term a predictor, as it predicts the actual range. This predictor has such a movement in respect to the index indicating the distance between the points 23 31 that it may be set to increase or reduce the reading of the distance indicated by said index to correspond to the greater or less estimated time that the projectile would take to reach the target owing to the change in position of thelatter, and the amount of movementof the predictor is governed by the time predicted determined by the velocity of the projectile. For instance, supposing from the reading of the range-tape of the instrument a ship is found to range seven thousand yards and that an inspection of the range-tables shows that fifteen seconds would be required for an eightinch projectile to travel to the target at that range, the predictor-finger is moved over the range-tape a distance equal to the travel of the range-tape during fifteen seconds and the reading on the tape opposite the end of the finger will be the predicted range for the tiring of the eight-inch projectile. This movement of the finger with respect to the tape will always be in reverse direction of travel of the tape, so as to reduce or increase the range as the target approaches or recedes.

yards.

An important feature of our invention con sists in making use of a plurality of predictors, so that while one predictor is being adjusted upon one portion of the tape the position of the other predictor may be'read and the range transmitted to the gun or guns in action.

Different arrangements of scales and predictors and different means of adjusting the predictors may be employed; but, as shown, the tape 40 is of such width as to operate in connection with a plurality of predicting-fingers 55, two sets of fingers being shown arranged side by side above the tape, each above a roller 84:, carried by a forked bar 85, (movable, as described hereinafter, when the instrument is used in connection with a battery of guns,) and below the tape and below each roller 84 is an eccentric 86 upon a shaft turning in bearings of the frame and provided with a handle 53. 1

The travel of the predicting-fingers in a direction opposite to that of the reading-tape for a period of time according to that of the predicted flight of the projectile is obtained by forcing the reading tape or ribbon 40 against the roller 84 above it by turning the eccentric-roller 86 to lift the tape into contact with the roller 84:, which may be done by swinging the lever 53. The roller 84 is always in contact with the lower side or edge of the predicting-finger 55 above it, which lower edge is preferably serrated to insure positive engagement, and when the traveling ribbon is forced upward against the roller 84: the latter will be caused to revolve and'will carry the predicting-finger with a speed equal to that of the tape, but in the opposite direction. 1

The time of prediction is obtained by means of a usual stop-watch reading half-seconds. The readings on the tape will be an actual plus or minus range corresponding to the increase or decrease of range for given time interval, which will be a function of velocity of the projectile. To insure constant correct prediction of both ranges and azimuth, a plurality of reading arrangements is provided by using a plurality of fingers-two being shown-so that continuous reading may not be interrupted. While one set of readings are being corrected for time of flight and consequent change in prediction, the readings are taken from the previously-corrected reading-points. The plus or minus prediction will hold good until a considerable change in rangetakes place, (from three hundred to six hundred yards for direct fire,) which is equal to one second change of time, corresponding to average velocity of projectiles. This will be a safe factor for mean ranges, and the prediction-lingers should be placed at their zero-marks or actual readings and a new prediction made for each change of time required when ranges differ more than six hundred The time function must be taken from tables showing the time of flight of given ICC projectiles in half-seconds for various ranges from two thousand to fifteen thousand yards.

When there is a number of guns in battery, we provide means for correcting the differences in range of target between the instrument and the differently-situated guns, so as to give the true range for each gun at the station instrument, from which point the corrected range is communicated to operators at the different guns. For this purpose the predicting-fingers are supported movably upon bars 85, of which there is one to each gun in battery, said bars being arranged to slide in guides 96 on the frame and each carried by a spring 87 toward a cam 50, which is connected rigidly to the stationary sectorplate, the frame 24 being free to move about the same as the telescope changes its position in azimuth. These cams 50 are respectively laid off from calculations of the relative positions of the instrument and the different guns in their different locations, and as the bars 87 carry the different predicting-fingers each of the latter will occupy a somewhat different position upon the tape and indicate a different range-reading from the others.

As there are duplicate fingers and duplicate readings, each bar 85 is forked to carry two fingers, one over each tape or each division of the tape, and each finger slides in a guide 88 on the bar with sufficient friction to retain its position after adjustment.

The position in azimuth is obtained by the movement of traversing the telescope and angle-bar about the pivot-point 23, said motion being communicated and increased in a ratio of one to twelve by gears 6]., shaft 62, and miter-gears 63 to a drum 64, on which is secured one end of the azimuth tape or ribbon 65, the other end passing over a guide-drum 101 and down to a spool-drum 67, on which it is kept tightly wound by spring-tension in a manner similar to the range-tape. Indicating or reading fingers 99 for each gun automatically corrected for the difference in azimuth of target from the instrument and the various guns give the true azimuth for each gun, the fingers being actuated by cams 79, laid off from calculations of the relative position of the instrument and the guns for any specific location. To enable continuous reading of azimuth positions, the scale may be duplicated, the ribbon or tape 65 being duplex or wide enough to coact with dup1icate fingers, as in the case of the range-scale. Predicting-fingers are also provided which are actuated by contact with the azimuthribbon for a given period of timeand in a manner similar to a given prediction for range. A prediction can be made for as much as two degrees of azimuth and for either direction Within one hundred and sixty degrees of arc.

The operation of the system is briefly as follows: Two men are stationed at the distant instrument B, No. 1 in charge of the telescope keeping the cross-hairs of the same constantly on point of target agreed upon between himself and No. 1 at the station instrument A, who is the observer at its telescope, both being in constant telephonic communication, each being fitted with a helmet telephonic receiver and transmitter. The sole and only duty of Nos. 1 is to keep the respective telescopes sighted on the point agreed upon. No. 2 at the distant instrument B reads the change in azimuth as it occurs and repeats the same to No. 2 of the station instrument A, Nos. 2 being fitted with helmet receivers and transmitters similar to the observers Nos. 1, but on a different me-' tallic telephonic circuit. No. 2 actuates the parts until the azimuth shown on the indexarm and minute-dial 82 corresponds to the transmitted azimuth from distant station E. The sole and only duties of the Nos. 2 are to transmit and keep the azimuths shown by the index-arms of the two instruments A and- B similar'and synchronous at all times. The chief in charge who is stationed at the station instrument looks at tables from which he obtains correct times of flight of projectiles for ranges indicated. He adjusts the predicting-fingers at suchintervals as he may deem necessary and has general charge of theinstruments under the fire director. Nos. 3, at, 5, and 6 are range and azimuth reporters, one for each gun in circuit. There may be as many as six reporters, but four is probably the greatest number of guns that should be served direct from one instrument, and the type designed is intended for this numher or less. The reporters are each in communication with a man at the gun he is serving by means of a system of metallic circuit telephone or other signaling means. In other words, each gun has two men on range and azimuth reporting duty, one of the men being stationed at the automatic indicator and the other at a position near the gun, the former constantly reading and sending and the latter repeating the predicted ranges and azimuths. The gun is traversed, elevated, or depressed continuously until in harmony with the repeated prediction, when it is fired. The angle of departure and azimuth of trajectory of projectile will then be such thatit should hit the target.

Fire control, greater accuracy, and continuous automatic predictions at ranges up to fifteen thousand yards are the principal features of this system of instrument.

The mechanical errors of instrument will not exceed ten yards for the greatest ranges when the same is constructed with the ordinary accuracy usually given this classof work. Allowing another ten yards (which equals one-half minute of are at extreme range) for error of observers, twenty yards will be the maximum error with instrument under ordinary circumstances.

The parts described may be mounted and operated in various ways. As shown, the segmental plates of the two instruments are supported each upon a pedestal 90, and the plate of the station instrument can be moved upon its support back and forth in a direction parallel to the base-line, dovetail projections 91 upon the plate 80 extending into a dovetail groove of a plate 92, bolted to a yoke 93, within which swings the frame 23. This allows the pivotal points of the two arms to be shifted to carry one from or to or over the other to the opposite side to secure ready and accurate changes in length of base-line to accurately proportion the miniature baseline 22 23 to the actual base-line terminating at A B. It also permits the instrument to be set so as to be either right or left handed, crossing the arm 29 by the arm 28 either from right or left.

The frame 24: is swung about the axis 23 by turning a hand-wheel 65, the shaft of which is geared by miter-gears 66 to a shaft 67, carrying a worm 68, that engages a worm-wheel 69 upon the pedestal.

The block 32 is moved back and forth to vary the intersecting-point of the two arms 28 29 by means of a screw 70, longitudinal with and turning in bearings of the arm 28 and extending through the lower end of the block 32, as a nut, so that the rotation of the screw moves the block 32 back and forth. The screw is rotated from a hand-wheel 71 through the medium of miter-gears 72, one on the shaft of the hand-wheel and the other on the end of the screw. The telescope 20 is carried by a standard 74 on the frame 24. and is provided with an adjustable arm 75, supporting a cross-bar 76, against which the operator who sights the instrument can bear with his chest when looking through the tele scope. These parts may be provided with any suitable adjusting means for varying their relative positions and securing them after adjustment.

To prevent confusion, we prefer to provide means whereby to identify the points on the scale which are to be read, as by securing the points on the scale where the predictonfingers are being adjusted. This may be effected in different ways, as by using a shifting hood'3, Fig. 2, which may be pivotedrorloose and shifted by hand from above one scale to the other.

Without limiting ourselves to the construction shown we claim- 1. The combination of two separate instruments, one at a station, the other at a distant point, each provided with a graduated segment, the edge of which coincides with or is parallel to a base-line between the two instruments, an arm and telescope moving therewith pivoted concentrically with the segment of the distant instrument, an arm 29 pivotedc onc'eutrically with the segment of the station instrument, and an arm 28 and telescope connected therewith, pivoted on the base-line of the station instrument at a different point from that of the arm 29, a sliding connection between the arms 28, 29 at their intersecting point and means for shifting the pivotal position of the two arms, substantially as set forth.

2. The combination of two separate instruments, one at a station, the other at a distant point, each provided with a graduated segment fixed points or graduations of which coincide with or are parallel to a base-line between the two instruments, an arm and telescope moving therewith pivoted concentrically with the segment of the distant instrument, an arm 29, pivoted concentrically with the segment of the station instrument, and an arm 28 and telescope connected therewith, pivoted on the base-line of the station instrument at a different point from that of the arm 29, a pin extending through the two arms 28, 29 at the point of intersection thereof and sliding along each arm, and means for shifting the pivotal points of the two arms, substan tially as set forth.

3. The combination of two separate instruments, one at a station, the other at a distant point, each provided with a graduated segment, the edge of which coincides with or is parallel to a base-line between the two instruments, an arm and telescope moving therewith pivoted concentrically with the segment of the distant instrument, an arm 29 pivoted concentrically with the segment of the station instrument, and an arm 28 and telescope connected therewith, pivoted on the base-line of the station instrument ata different point from that of the arm 29, a sliding pin extending through the two arms 28, 29, at the point of intersection thereof, means for indicating variations in the distance between the pivotpoint and intersecting-point from the arm 28 as the two arms 28, 29 swing about their pivots, and means for communicating changes in the positions of the parts between observers at the two instruments and a gun or guns in battery, substantially as set forth.

4. In a range and azimuth finder, the combination of a graduated segment, an arm 29 pivoted concentrically with the segment, an arm 28 pivoted at an adjacent point intersecting the arm 29, a sliding connection between the arms at the point of intersection, sighting means in line with the arm 28 and means for shifting the pivotal points of the two arms, to carry the pivotal points toward or over each other, substantially as set forth.

a 5. The combination in a range and azimuth finder, of a supporting-pedestal, a graduated segment and means for shifting the latter upon its support in a direction parallel to the straight edge of the segment, an arm 29 pivoted concentrically with the segment, a sighting device, and an arm 28 in line with the sighting device and pivoted to a point on the support eccentric to the pivot-point of the arm 29, and a sliding connection between the arms 28, 29 at a point of intersection thereof, substantially as set forth.

6. In an azimuth-finder, the combination of a graduated segment, an arm 29 pivoted con- IIO centrically with the segment, an arm 28 pivoted at an adjacent point and intersecting the arm 29, a sliding connection between the arms at the point of intersection, sighting means in line with the arm 28 and means for shifting the pivotal points of the two arms, and a scale for indicating the varying dis tances between the intersecting-point and pivot of the arm 28 as the, two arms change their position, substantially as set forth.

7. In an azimuth-finder, the combination of a graduated segment, an arm 29 pivoted concentrically with the segment, an arm 28 pivoted at an adjacent point and intersecting the arm 29, a sliding connection between the arms at the point of intersection, sighting means in line with the arm 28, means for-shifting the pivotal points of the two arms, a graduated tape secured at one end near the pivot of the arm 28, a pulley connected to be carried with the pin at the intersecting-point of the arms and around which the said tape passes, and a drum to which the tape is carried, with means for winding the tape upon the drum and permitting its delivery as required, substantially as set forth.

8. The combination with the graduated segment, intersecting arms, a pin and sliding block carried by one of the arms, a pulley carried by said block, a tape fixedly connected at one end and passing around said pulley, and a spring-drum upon which the tape is wound at the other end, substantially as set forth.

9. The combination of a graduated segment, pivoted intersecting arms, sliding pin at the point of intersection, scale for indicat ing the distance between said pin and the pivot of one of the arms, a finger, and means for altering the position of the same on said scale toincrease or decrease the reading thereof, substantially as and for the purpose set forth.

10. The combination of the graduated seg ment, intersecting arms pivoted at difierent points, one concentric with said segment, a sliding connection at the point of intersection of the two arms, a tape having a scale indicating the distance between the pivot of one of the arms and the said connection and connected to travel therewith, a finger extending over the tape, and means for shifting the finger by and proportional to the movement of the tape, but in a reverse direction for any desired interval to add to or subtract from the reading of the tape, substantially as and for the purpose described.

11. The combination of the graduated segment, pivoted, intersecting arms, traveling scale, finger extending over said scale, a roller between the finger and the scale, and means for lifting the scale into contact with the roller to thereby shift the finger in a direction the reverse of that in which the scale is traveling, substantially as set forth.

12. The combination of the graduated segment, intersecting arms pivoted at different points, graduated tape, means for shifting the same to correspond to changes of distance of the intersecting point from the pivots, finger extending over the tape, a roller in contact with the under side of the finger, an eccentric beneath the tape, and means for turning it to bring the tape into contact with the roller, substantially as set forth.

13. The combination of a graduated segment, pivoted, intersecting arms, movable scale for indicating a change of distance of the point of intersection from the pivot of one of the arms, and a plurality of fingers inde pendently movable in respect to the scale to increase or decrease the reading thereof, whereby one scale may be read while the position of the finger on the other is being shifted, substantially as set forth.

14. The combination with a gun, of means for indicating the range and azimuth of a moving target includinga shifting scale, and a finger movable in respect to said scale whereby to add to or subtract from the reading thereof in proportion to the time required for a projectile to reach the target, substantially as set forth.

15. The combination with a gun, of means for indicating the range and azimuth of a moving target including a shifting scale,and a plurality of fingersindependent ly movable in respect to said scale whereby to add to or subtract from the reading thereof to permit the indications to be read in connection with one of the fingers while the, other is being shifted, substantially as setforth.

16. The combination with a battery ofguns, of meansforindicating the range and azimuth of a moving target, including a shifting scale, a finger movable in respect to said scale whereby to add to or subtract from the reading thereof, in proportion to the time required for the projectile to reach the target, and means for communicating theindications of the scale independently to the different guns, substantially as set forth.

17. The combination with a gun, of a station instrument and a distant. instrument, each with a means for finding the azimuth of a moving target, means at the station instrument for also indicating the range including ashiftipg scale and a finger movable in respect tb said scale whereby to add to or subtract from the reading thereof in proportion to the time required for a projectile to reach the target, and means for communicating the indications at the different instruments to the different guns, substantially asset forth.

18. The combination with a gun, of means for indicating the range and azimuth of a moving target, including a shifting scale, a finger and means for shifting the finger in a .reverse direction to the movement of the scale during the predicted intertttal of time required for the flight of a. projectile between the gun and target, substantially as set forth.

19. The combination with a stationarygraduated scale of an arm 28 pivoted concentrically therewith, a swinging frame carryingan "arm 29 intersecting the arm 28 and pivoted eccentric-ally to the latter, a tape graduated to indicate changes of azimuth, means for shifting the tape as the frame swings about its pivot, and a finger movable in respect to said tape to increase or decrease the indications thereof in proportion to predicted changes of azimuth, substantially as set forth.

20. The combination with a gun, of means for indicating the range and azimuth of a moving target including independent range and azimuth scale tapes or bands, and means for altering the indications thereof according to estimated changes in range and azimuth, substantially as set forth.

21. The combination with a gun, of means for indicating the range and azimuth of a moving target including independent range and azimuth scales and means for altering the indications thereof according to estimated changes of range and azimuth, and a finger movable in respect to each scale whereby to add to or subtract from the reading thereof in proportion to the estimated changes of range or azimuth during the flight of a projectile and change of position of the target,

substantially as set forth.

22. The combination with a battery of guns, of a station instrument having range and azimuth finders and means for indicating the estimated change of range and azimuth of a moving target including a shifting scale, a series of fingers, one for each gun adjusted upon the scale in accordance with the differences in distance and azimuth of the different guns in respect to the target, and means for 40 preservingthedifferentrespectiveindications upon the scale during the movements of the range and azimuth finders, substantially as set forth.

The combinationinarange and azimuth finder, of a stationary graduated segment,arm pivoted concentrically therewith and intersecting arm and sighting device swinging about another pivot-point, means fol-indicating the estimated changes of range and azimuthincludingashifting scale andindependent fingers, one for each gun, extending over said scale, and a cam for shifting the position of each finger, and means for moving the cams as the range and azimuth finders are moved, substantially as set forth.

24. The combination of the pedestal, stationary graduated segment and arm pivoted concentrically therewith, a frame carrying another arm intersecting the first, and pivoted at another point and carrying a sighting device, a graduted azimuth-tape, drums upon which said tape is wound, and gearing be tween the swinging frame and one of said drums, substantially as set forth.

25. The combination of the pedestal, stationary graduated segment and arm pivoted concentrically therewith, a frame carrying another arm intersecting the first, and pivoted at anotherpointand carrying a sighting device, a graduated azimuthtape, and a spring-actuated drum on which said tape is wound, substantially as set forth.

26. The combination of the swinging frame, stationary graduated segment and intersecting pivoted arms, of a sighting device carried by the frame, and transverse support 76 also carried by the frame below the sighting devices, substantially as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

JOHN F. MEIGS. EMIL GATI-IMANN. Witnesses:

WILLIAM E. HORNE, EDWIN A. 1\/[ILLER. 

